The Attitudes to Ageing Questionnaire:Mokken Scaling Analysis

BACKGROUND:Hierarchical scales are useful in understanding the structure of underlying latent traits in many questionnaires. The Attitudes to Ageing Questionnaire (AAQ) explored the attitudes to ageing of older people themselves, and originally described three distinct subscales: (1) Psychosocial Loss (2) Physical Change and (3) Psychological Growth. This study aimed to use Mokken analysis, a method of Item Response Theory, to test for hierarchies within the AAQ and to explore how these relate to underlying latent traits. METHODS:Participants in a longitudinal cohort study, the Lothian Birth Cohort 1936, completed a cross-sectional postal survey. Data from 802 participants were analysed using Mokken Scaling analysis. These results were compared with factor analysis using exploratory structural equation modelling. RESULTS:Participants were 51.6% male, mean age 74.0 years (SD 0.28). Three scales were identified from 18 of the 24 items: two weak Mokken scales and one moderate Mokken scale. (1) 'Vitality' contained a combination of items from all three previously determined factors of the AAQ, with a hierarchy from physical to psychosocial; (2) 'Legacy' contained items exclusively from the Psychological Growth scale, with a hierarchy from individual contributions to passing things on; (3) 'Exclusion' contained items from the Psychosocial Loss scale, with a hierarchy from general to specific instances. All of the scales were reliable and statistically significant with 'Legacy' showing invariant item ordering. The scales correlate as expected with personality, anxiety and depression. Exploratory SEM mostly confirmed the original factor structure. CONCLUSIONS:The concurrent use of factor analysis and Mokken scaling provides additional information about the AAQ. The previously-described factor structure is mostly confirmed. Mokken scaling identifies a new factor relating to vitality, and a hierarchy of responses within three separate scales, referring to vitality, legacy and exclusion. This shows what older people themselves consider important regarding their own ageing

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

SARS-CoV-2-specific immune responses and clinical outcomes after COVID-19 vaccination in patients with immune-suppressive disease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune responses and infection outcomes were evaluated in 2,686 patients with varying immune-suppressive disease states after administration of two Coronavirus Disease 2019 (COVID-19) vaccines. Overall, 255 of 2,204 (12%) patients failed to develop anti-spike antibodies, with an additional 600 of 2,204 (27%) patients generating low levels (<380 AU ml−1). Vaccine failure rates were highest in ANCA-associated vasculitis on rituximab (21/29, 72%), hemodialysis on immunosuppressive therapy (6/30, 20%) and solid organ transplant recipients (20/81, 25% and 141/458, 31%). SARS-CoV-2-specific T cell responses were detected in 513 of 580 (88%) patients, with lower T cell magnitude or proportion in hemodialysis, allogeneic hematopoietic stem cell transplantation and liver transplant recipients (versus healthy controls). Humoral responses against Omicron (BA.1) were reduced, although cross-reactive T cell responses were sustained in all participants for whom these data were available. BNT162b2 was associated with higher antibody but lower cellular responses compared to ChAdOx1 nCoV-19 vaccination. We report 474 SARS-CoV-2 infection episodes, including 48 individuals with hospitalization or death from COVID-19. Decreased magnitude of both the serological and the T cell response was associated with severe COVID-19. Overall, we identified clinical phenotypes that may benefit from targeted COVID-19 therapeutic strategies

Partitioning of items across Mokken scales with increasing lowerbound values of Hs (n = 802).

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099100#pone-0099100-t002" target="_blank">Table 2</a> for item labels.</p><p>* =  too few items to form a scale.</p><p>DNS = did not scale.</p

Principal components analysis with oblimin rotation of the AAQ.

<p>*See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099100#pone-0099100-t002" target="_blank">Table 2</a> for the labelling of items.</p>a<p>For clarity loadings on putative factors are shown in bold and only the places after the decimal point are shown.</p

Pearson's correlation between AAQ dimensions and a range of variables.

<p>HADS = Hospital Anxiety and Depression scale; NEO-FFI = NEO Five Factor Index;</p><p>* = p<0.05; ** = p<0.01;</p><p>Note: in this table, higher scores on the AAQ dimension of Vitality indicates a more positive attitude; higher scores on Legacy indicate a more positive attitude; and higher scores on Exclusion indicate a more negative attitudes towards ageing.</p

Mokken scaling of the Attitudes to Ageing Questionnaire with items ordered according to their mean score (n = 802).

<p>(-) used to indicate that analyses reverse-scored these items.</p><p>DNS = did not scale.</p><p>AAQ Factor  =  Factor as derived in original factor analyses <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099100#pone.0099100-Laidlaw1" target="_blank">[12]</a>.</p><p>For mean scores, scores are on Likert scale, 1 =  strongly disagree, 3 =  neither agree nor disagree, 5 =  strongly agree; a high score indicates a more negative attitude towards ageing.</p><p><b><i>Mokken Scale 1: Vitality/Person focussed ageing</i></b>: Hs = 0.37; Rho = 0.80; p = 0.00012; H^T = 0.23.</p><p><b><i>Mokken Scale 2: Legacy/Social value</i></b>: Hs = 0.46; Rho = 0.74; p = 0.00031; H^T = 0.31;</p><p><b><i>Mokken Scale 3: Exclusion/Social role</i></b>: Hs = 0.39; Rho = 0.78; p = 0.00047; H^T = 0.07.</p

Correlation between error variances.

<p>*See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099100#pone-0099100-t002" target="_blank">Table 2</a> for the labelling of items.</p